24 Ranges library [ranges]

24.6 Range factories [range.factories]

24.6.2 Empty view [range.empty]

24.6.2.1 Overview [range.empty.overview]

empty_­view produces a view of no elements of a particular type.
[Example 1: auto e = views::empty<int>; static_assert(ranges::empty(e)); static_assert(0 == e.size()); — end example]

24.6.2.2 Class template empty_­view [range.empty.view]

namespace std::ranges { template<class T> requires is_object_v<T> class empty_view : public view_interface<empty_view<T>> { public: static constexpr T* begin() noexcept { return nullptr; } static constexpr T* end() noexcept { return nullptr; } static constexpr T* data() noexcept { return nullptr; } static constexpr size_t size() noexcept { return 0; } static constexpr bool empty() noexcept { return true; } }; }